<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<style>
    body{
        font-size:10px;
    }
    p{
        font-size: 1rem;
    }
</style>
<p>哈哈</p>
</body>
</html>